Combined transmitter and receiver



'w. w. DEAN. COMBINED TRANSMITTER AND RECEIVER.

APPLICATION FILED MAY 4. I916.

Patented Jun 21, 1921.

swans-sum 1- W. W. DEAN.

COMBINED TRANSMITTER AND RECEIVER.

APPLICATION FILED MAY 4| I916.

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W. W. DEAN.

COMBINED TRANSMITTER AND RECEIVER.

APPLICATION FILED MAY 4' I916 Patented June 21, 1921.

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[Ru [Tar Zz'cmz ZZZ 12am .z i rneg s UNITED STATES PATENT OFFICE,

WILLIAM W. DEAN 0F ROCEESTER, NEW YORK, ASSTG-NOR T0 STROMBERG-CARLSON TELEPHONE IIIAN'UFACTURING COMPANY, OF ROCHESTER, NEW YORK, A CORPO- RATION OF NEW YORK.

GOMBHIED TRANSMITTER AND RECEIVER.

Application filed. May 4,

1 0 all whom it may can 061%:

Be it known that T, WILLIAM V7. DEAN, a citizen oi the United States, residing at Rochester, in the county of Monroe and State of New York, have invented a certain new and useful improvement in Combined iransmitters and Receivers, of which the following is a full, clear, concise, and exact description, reference being had to the ac companying drawings, forming a part of this specification.

My invention relates to telephones and more. particularly to instruments of the combined transmitter and receiver type. Tnstruments of this type have proven to be practical and convenient, but as heretofore constructed have been heavy, clumsy, and expensive to construct.

My invention aims to provide a telephone of this class which is characterized by durability, lightness, good operating qualities and low cost of manufacture. In the accompanying drawings in which I have illustratcd one embodiment of my invention,

Figure l is an elevational view showing the telephone in side elevation and the switch and casing in front elevation;

Fig. 2 is a longitudinal section of the in strument;

Fig. 3 is a front elevation of the receiver with the ear cap and diaphragm removed;

Fig. 4C is a longitudinal section taken at right angles to Fig. 2 of the transmitter casing, showing the transmitter bridge in elevation;

Fig. 5 is a rear elevation of the receiver;

Fig. 6 is a cross section of the transmitter and easing, taken just back of the transmittcr diaphragm;

Fig. 7 is a rear detail view of the receiver electromagnet; and

Fig. 8 is a plan elevation o'f'the same.

The instrument comprises a receiver 1, a transmitter 2, and a handle 3 which connects the transmitter and receiver. A. flexible cord 4L maintains the circuit between the instrument and the stationary terminals 5 which are connected to the line wires. The terminals 5 are mounted upon a block of insulation 6 that is, in turn, connected to the top of the switch casing 7 which forms a suitable cover for the automatic switch which opens and closes the circuit to the instrument. This switch is connected in Specification of Letters Patent. Patented J 11110 21, 1921.

1916. Serial No. 95,396.

and a flange 14 at the open end thereof.

The section 12 comprises a cup with an apertured bottom part 15, and an inturned flange 15' which forms a wide seat for the diaphragm 16. Just back of the flange 15 the shell 12 is expanded for a short distance andupon the expanded portion 17, suitable screw-threads are formed which cooperate with the threads formed on the ring or ferrule 18. The ferrule 18 has an inturned flange for engaging the shoulder 19 upon the hard rubber ear cap 20. The cap 20 is provided upon its rear side with a ridge or ring 21 which presses the diaphragm. 16 firmly against the seat 15. v

The magnet system which is employed in the receiver comprises a plurality of E- shaped stampings 22 which are suitably bound together by non-magnetic cheeks or blocks as is set forth in my co'pending ap plication, Serial No. 96,469, filed May 10th, 1916. The bottom of the stampings is faced off flush with the cheek pieces 23 and suitable machine screws 24: hold the cheek pieces 23 and the ends of the iron stampings against the bottom of the cup 11. The eye 9, by which the instrument is suspended, is

- clamped against the flange 14 by means of suitable screw bolts which pass into the bottom 15 of the casing 12. The aperture in thebottom 15 is just large enough to receive the magnet systems to permit the same to be readily assembled. T'Vhen the magnet has been mounted in the shell 11, the shell is filled with wax to the level of the apertured bottom part 15 of the shell 12. This wax has the two-fold function of impregnating the magnet winding and the connections thereto and preventing the singing of the transmitter diaphragm which would otherwise be caused by the undulations of the receiver diaphragm being transmitted from the receiver shell to the transmitter shell through the tubular handle 3. The handle 3 comprises an outer sleeve 27 of insulating material, preferably a hard close grained wood and an inner metal tube 28 which joins the casing of the receiver 1 and the transmitter 2.

The manner of attaching the tube 28 to these casings is considered by me to be novel. The bottom of the cylindrical portion of the casing 11 is ape-rtured and threaded to receive the end of the tube 28 which is also threaded.

The threaded aperture in the side wall of this casing 11 is substantially tangent to the bottom wall 13 so that the end of the tube 28 will lie substantially tangent to the bottom wall 13 when the tube is threaded into the aperture.

When the tube 28 has been threaded into place in the casing 11, the side of the tube 28 which faces toward the open end of the casing is milled away, as is shown in Fig. 2, and the opposite side of the tube is attached to the bottom 13 of the casing by means of the rivet 29.

The lower end of the tube 28 is attached in a similar manner to the back 30 of the transmitter casing 31 by means of the rivet 32. It is to be noted that in proportion to the diameter of the casing 31 the walls of the casing are relatively thin. In order to secure a good hold for the threads on the end of the tube 28, the aperture formed in the casing 31 is formed with an inturned flange, as is illustrated in Fig. 2 and Fig. 4, at detail 33. A hole is drilled at 34 in the side wall of the tube 28 adjacent the end thereof to facilitate the insertion of the rivets 32. The hole 34 also forms a convenient support for the end 35 of the jacket of the flexible cord 4 which enters the casing at 31 at a point directly below the place where the tube 28 enters the casing 31. A suitable eyelet 36 binds the edges of the shell about the aperture to prevent cutting of the cord ,4.

The front plate 37 of the transmitter is formed with a flange 38 which fits into the open end of the casing 31 and is secured to said casing by means of the screws 39 and suitable bayonet slots, as illustrated in Fig.

1. It is to be noted that for the convenience of manufacture, I form the transmitter shell 31 of a suitable diameter to receive a standard size of transmitter.

The front plate 37 is provided with a suitable boss 40 for receiving the mouth piece 41. The mouth piece 41 is formed of semi- .vulcanized rubber and is therefore quite tough to resist breakage. The toughness and softness of the material renders it unsuited for the formation of screw-threads and hence it has not been popular due to the difficulty of fastening such a mouthpiece to the transmitter. I have provided novel fastoning means for the mouth-piece 41. The inner reduced end 42 of the mouth-piece is given a slight taper and the boss 40 is bored on a similar taper so that when the mouthpiece is forced into the bore of the boss the two will be firmly held together by friction. To preserve the alinement of the mouth piece with respect to the rest of the instrument, T have provided the same with a groove 43 upon the bottom side. A stud 44 which fits loosely in a hole formed in the boss 40 is threaded at its outer end, as shown in Fig. 2, to coperate with threads formed in the strap 45. The strap 45 is secured to the boss by small machine screws. It is to be noted that the pin 44 is not threaded along its entire len th but is threaded only at its outer extremity. This is to prevent the pin from dropping out of the strap 45. The pin 44 has a rounded end which lies in the slot 43 in the shank of the mouth-piece and prevents the mouthpiece from being turned and thereby loosened. V The taper joint is depended upon solely for holding the parts together and the pin 44 is. not intended to stand the strain of supporting the mouthpiece.

The transmitter which is illustrated in the accompanying drawings is of the type disclosed and claimed in my co-pending application Serial No. 103,090, filed June 12th, 1916.

This transmitter has a bridge 47 which is secured at its ends to the flange 38. At the center the bridge piece 47 supports a terminal block 48 to which the cup and rear electrode of the carbon button 49 are secured by means of the stem 50. Upon each side of the terminal block 48 are insulated contacts or terminals 52 and 53 for making con nection with the various conductors and with j the electrodes of the transmitter. The diaphragm 54 is connected by means of a flexible flat conductor member 55 with the insulated terminal piece 52. The terminal piece 52 is connected by means of the conductor 57 which passes up through the tube 27 to one terminal of the electromagnet winding 58 of the receiver. The other termi nal block 53 forms a suitable connection between the one strand 59 of the flexible cord 4 and the wire 60 which passes up through the tube 28 and connects with the other terminal of the winding 58 of the receiver. The diaphragm is insulated from the front plate 37 by a washer or ring61 of in.- sulating material, preferably celluloid. The diaphragm is placed under tension by means of the two spring fingers 62 and 63 which have their ends or edges engaging the diaphragm at points diametrically across from the attachment of the front electrode.

The end 64 of the flexible cord 4 is attached to the terminal block 48. The circuit through the instrument may be traced as follows: from one of the terminals 5 through the hooL-switch flexible cord 4, through the strand 59, connecting block 53, wire 60, winding 58 of the electro-magnet, wire 57 to the terminal block 52 from the block 52 to the conductor 55 to the front electrode of the granular carbon button 49 through the carbon grains, the back electrode, to terminal block 48 and from thence through the strand 64 of the cord 4e and back to the other terminal 5.

It can be seen that my invention dispenses with the usual terminal block which is re quired to connect the interior wires of the instrument with the flexible leads. The bridge of the transmitter serves as a suitable connecting block for making such connection.

It can be seen that my invention provides an instrument of graceful appearance, but of rugged construction and of low cost of manufacture. A full sized model which I have constructed weighs less than 16 ounces but is amply strong to withstand continuous service.

What I claim is:

1. Ina device of the class described, a relatively thin sheet metal shell for housing a telephone instrument, a handle member for said housing, said handle member comprising a thin walled metal tube, said shell having a threaded opening in one side wall which opening is substantially tangent toan adjacent wall, said tube being threaded into said opening and projecting into the shell substantially tangent to said latter wall, and a rivet passing through said latter wall and the adjacent side wall only of said tube, said rivet passing through the wall of the shell and the wall of the tube beyond the threaded opening and holding the tube against turning in the threads and also holding the end of the tube rigidly in contact with said tangent wall.

2. In a telephone, a shell having a sub-' stantially cylindrical portion, an end por tion closing off said cylindrical portion, an aperture in said cylindrical portion adjacent said. end, said aperture having its ends inturned, a metal tube threaded into said inturned portion, and a rivet securing said tube to the end of said shell.

In combination a cylindrical. shell having a closed end, said shell being apertured, the edges of said shell adjacent said aperture being inturned and threaded, a metal tube threaded into said aperture, said tube having an opening through one wall thereof adjacent the end of the tube, said opening lying within said shell and a rivet securing the opposite wall of said tube to the end wall of said shell.

4. In combination a receiver shell comprising a cup having a flanged edge, a cup of larger diameter having an aperture through the bottom thereof, the flange of said first cup surrounding said aperture, an electromagnet having its rear end resting against the bottom of said first cup and its front end lying a short distance below the rim of the second cup and a filling of wax surrounding said magnet and filling said first cup.

In a receiver, a cup having a closed bottom and a flanged rim, a secondcup having an aperture in the bottom thereof, said cup having its edge flanged inwardly and faced off to form a seat for a diaphragm, said cup having a bead projecting outward rom the side walls thereof, said bead being threaded and a receiver cap adapted to be held in place by said threads.

6. In a telephone, a cylindrical cup having an aperture in the bottom thereof, the edges of said cup being flanged inwardly, said cup having a bead adjacent said flange, said bead extending outward and being threaded and a receiver cap secured to said threads.

7. In combination, a cup having a closed bottom, the edge of said cup being flanged outwardly, a second cup of larger diameter, said cup having an aperture in the bottom thereof, the flange of said first cup lying flat against the bottom of said second cup,

a suspending lug lying back of the flange of said first'cup and means for securing said lug, said flange and the bottom of said second cup together.

8. In combination, a receiver shell, a transmitter shell, a tube joining the interiors of said shells, the endof said tube projecting into said transmitter shell, said projecting end being apertured, a flexible cord passing into said transmitter shell, said cord having its jacket secured to the end of said apertured tube.

9. In combination a transmitter shell, a tube threaded into said transmitter shell, a handle on said tube, a transmitter in said shell, said transmitter having a bridge, a

flexible cord entering said transmitter shell and having its jacket secured to the end of said tube, a plurality of insulated contacts mounted on said. bridge, a plurality of the strands of said cord being connected to said insulated contacts. 7

10. In a combined transmitter andreceiver, a receiver, a transmitterhavingatransmitter bridge, means on said bridge for supporting a granular carbon button, said means being connected to one terminal of the button and being insulated from said bridge, a pair of terminals mounted on said bridge, one of said terminals being insulated from said bridge, the other bridge terminal being connected tothe opposite terminal of the button, a casing surroundingsaid transmitter bridge, a flexible 'cord passing through said casing, and having one of its strands secured to said means and another of its strands secured to one of said bridge terminals, and conductors between said bridge terminals and the receiver to put the transmitter and the receiver in series With said cord. 1

l1. .ln a combined transmitter and receiver, a bridge member in the transmitter, a fixed electrode mounted on the bridge, aplate insulated from the bridge and connected to the fixed electrode, a movable electrode, a pair of connector bars on the bridge, one thereof insulated from the bridge, receiver circuit Wires connected one to each bar, a two Wire cord entering the transmitter, one Wire thereof connected to said insulated bar, the other connected to said plate, and means rennecting the other bar with the movable electrode, whereby the bridge serves as a terminal block for connecting the several circuits. 7

12. In combination transmitter shell, a tube enteringsaid shell, the end 01 said tube projecting into said transmitter shell,

said projecting end being apertured, a flexi- 

